Add a copysign test case that bit me in a state I can't reproduce.

diff --git a/tests/runtime/test-arith.scm b/tests/runtime/test-arith.scm
index 379dc8215547be9d598ffdfe4c06e7443862775d..9c02f2f71fb3172a946776b957debbe4c085df82 100644 (file)
--- a/tests/runtime/test-arith.scm
+++ b/tests/runtime/test-arith.scm
@@ -936,7 +936,8 @@ USA.
     (,(flo:make-nan #f #f 1) 1 ,(flo:make-nan #f #f 1))
     (,(flo:make-nan #t #f 1) 1 ,(flo:make-nan #f #f 1))
     (,(flo:make-nan #f #f 1) -1 ,(flo:make-nan #t #f 1))
-    (,(flo:make-nan #t #f 1) -1 ,(flo:make-nan #t #f 1)))
+    (,(flo:make-nan #t #f 1) -1 ,(flo:make-nan #t #f 1))
+    (1/4 -1/8 -1/4))
   (lambda (x y z)
     (assert-eqv-nan (yes-traps (lambda () (copysign x y))) z)
     (assert-eqv-nan (yes-traps (lambda () (copysign (- x) y))) z)